U.S. Pat. No. 5,224,405 discloses a transfer roll 28 provided with a plurality of puck assemblies 54 for receiving web strips 18, 20 from a cutting assembly 4 and for rotating and transferring them to a substrate 14. Each puck assembly 54 comprises a generally rectangular, pivotable puck 74. The pucks 74 are capable of rotating with the transfer roll 28 about its axis of rotation and, further, are capable of rotating about an axis transverse to the axis of rotation of the transfer roll 28. However, the pucks 74 do not rotate about a further axis generally parallel to the axis of rotation of the transfer roll 28 during transfer of a web strip 18, 20 from a vacuum anvil roll 32 to a puck 74. Hence, a gap between a strip 18, 20, secured to the vacuum anvil roll 32, and the puck 74, during transfer of the web strip 18, 20 from the cutting assembly 4 to the puck 74, may vary substantially unless the puck 74 is generally deformable so as to deform to the shape of the anvil roll 32 during workpiece transfer. If the gap between the strip/anvil roll and the puck 74 increases substantially during workpiece transfer, improper transfer of the strip 18, 20 to the puck 74 may occur due to the vacuum from the puck 74 being insufficient at the larger gap size to pull the strip 18, 20 to the puck 74.
International Application WO 00/00419 also discloses a workpiece transfer apparatus. The apparatus comprises a rotatable drum 30 having a plurality of rotatable transfer shafts 35 positioned near the drum perimeter. Each transfer shaft 35 comprises at least one transfer head 40 for receiving material from a source A. It is noted that rotation of the transfer shafts 35 is effected using a mechanical camming arrangement. Such a mechanical control arrangement is difficult to modify to accommodate workpieces of different sizes, or vary the pitch or distance between workpieces delivered to another workpiece, e.g., a continuous web, or a conveyor.
Accordingly, there is a need for a transfer device having a workpiece gripping member mounted to a rotatable shaft which, in turn, is mounted to a rotatable drum such that the gripping member rotates with the drum, rotates about an axis parallel to the drum's axis of rotation, and, if desired, can be controlled so as to rotate about an axis transverse to the drum's axis of rotation. There is also a need for a transfer device having a workpiece gripping member mounted to a rotatable shaft which, in turn, is mounted to a rotatable drum where the rotation of the shaft and, hence, the gripping member, is effected by a drive arrangement more versatile than a mechanical camming arrangement.